1. Field of the Invention
The present invention relates to a vehicle, and more specifically, a passive safety device that prevents an occupant from moving against an acceleration working on the occupant in the vehicle while the vehicle is traveling.
2. Description of the Related Art
Conventionally, when a vehicle is traveling, if sudden braking, turning together with deceleration, and acceleration, etc., happens, an acceleration is applied in some cases to an occupant in the vehicle in such a way that the occupant is moved in the vehicle due to inertia force.
In order to overcome such a problem, so far, a pretensioner is proposed which reduces the amount of movement of the occupant by increasing/decreasing the tension of a safety belt worn by the occupant sitting down a seat.
Also, a seat control to move the seat, where the occupant is sitting, back and forth and to change the tilting angle of the backrest of the seat back and forth is known.
Regarding the pretensioner and a seat control, Japan Patent No. 4285569 (see, for example, [0030], [0058], FIG. 1, and FIG. 7) discloses a “passive safety device comprising seat adjusting means for adjusting a condition of a seat in an appropriate condition, belt adjusting means for adjusting the tension of a safety belt, determining means for determining whether or not it is necessary to adjust the condition of the seat and the tension of the safety belt, and control means for controlling the seat adjusting means and the belt adjusting means when the determining means determines that it is necessary to adjust the condition of the seat and the tension of the safety belt, in such a manner that the belt adjusting means starts adjustment after the seat adjusting means terminates adjustment, or that the belt adjusting means starts adjustment after the seat adjusting means starts adjustment and the seat adjusting means terminates adjustment when a predetermined tension is about to be applied to the safety belt by adjustment of the belt adjusting means”, which is recited in claim 1.
According to the configuration of Japan Patent No. 4285569, either one of the safety belt or the seat is controlled, so that the control cannot keep up with an acceleration working on the vehicle and the occupant is not held appropriately in some cases, resulting in an uncomfortable feeling to the occupant.
The present invention has been made in order to overcome the foregoing problem, and it is an object of the present invention to provide a passive safety device which can prevent an occupant from moving when an acceleration that causes the occupant to move in a vehicle is applied to the occupant, and which can improve the ride quality.